Underwater communication between a vessel and a structure and vessel-positioning means

ABSTRACT

An underwater communicating connection between a marine vessel, such as a submarine, and a structure, such as a dock or underwater caisson or another marine vessel, for the passage of personnel, is formed by juxtaposing the vessel and structure to isolate a water-containing space between watertight doors on the vessel and structure, removing water from the space, and admitting air at subaqueous pressure, whereby the vessel is forced against the structure by hydrostatic pressure; the doors are then opened. A flexible sealing member outside of the connection on the vessel or structure may engage a sealing surface on the other for additional sealing. The dock may include a tower extending to the water surface. The vessel can be positioned by anchors resting on a platform or engaged to a frame fixed to the ground.

United States Patent Greene Mar. 7, 1972 [54] UNDERWATER COMMUNICATION BETWEEN A VESSEL AND A STRUCTURE AND VESSEL- POSITIONING MEANS [72] Inventor: Clarence Kirk Greene, 115 Woodside Road, Berkeley, Calif. 94708 [22] Filed: Feb. 11, 1970 [211 Appl. No.: 10,321

[52] U.S.Cl. ..61/69 A, 114/16 [58] Field of Search ..61/69 R, 46, 46.5, 83, 63, 61/67, 68, 72.3, 81, 69 A; 114/15, 16, 16.4,

FOREIGN PATENTS OR APPLICATIONS 120,102 10/1918 Great Britain... ..61/69 Primary Examiner-J. Karl Bell Attorney-Milmore & Cypher [57] ABSTRACT An underwater communicating connection between a marine vessel, such as a submarine, and a structure, such as a dock or underwater caisson or another marine vessel, for the passage of personnel, is formed by juxtaposing the vessel and structure to isolate a water-containing space between watertight doors on the vessel and structure, removing water from the space, and admitting air at subaqueous pressure, whereby the vessel is forced against the structure by hydrostatic pressure; the doors are then opened. A flexible sealing member outside of the connection on the vessel or structure may engage a sealing surface on the other for additional sealing. The dock may include a tower extending to the water surface. The vessel can be positioned by anchors resting on a platform or engaged to a frame fixed to the ground.

24 Claims, 15 Drawing Figures PATENTEDMAR 7:972 3,646,771

SHEET 1 UF 5 FIG.

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CLARENCE KIRK GREENE 'fl/M a HIS ATTORNEYS UNDERWATER COMMUNICATION BETWEEN A VESSEL AND A STRUCTURE AND VESSEL- POSITIONING MEANS The invention relates to an underwater communicating connection between a water-immersed, marine vessel and another structure, such as a stationary or mobile dock, another vessel, or an underwater caisson, to permit personnel and/or goods to move between the vessel and the structure. The invention is especially, although not exclusively, useful for mooring a submarine which is completely submerged to a dock or to an underwater caisson,such as a service room for underwater well drilling, to enable personnel to leave or enter the submarine beneath the water.

In the transportation of goods, such as liquid petroleum, by submarines which operate beneath a surface layer of ice, it is desirable to moor the submarine in the unfrozen water beneath the ice in a manner to permit personnel or goods to pass between the submarine and another enclosure, which may be a dock situated under the water and includes a tower extending to the surface above the ice through which personnel can ascend. The alternative of breaking the ice to permit the submarine to surface is often not feasible and can result in immobilization of the submarine when the water again freezes. Similarly, it is at times desirable to establish an underwatercommunicating connection from the submarine to a mobile structure, such as another vessel or to an underwater caisson, such as a service room housing personnel at atmospheric pressure for drilling or completing an underwater well or operating and servicing pumping equipment.

It is, further, desirable to provide a system for mooring a submarine beneath the water surface, which may or may not bear ice, especially near the ocean floor, in a manner to permit the transfer of personnel and/or the loading or unloading of cargo, whether solid, liquid or gaseous. This is because there are often no currents or no strong or variable currents at such depths and the water is not strongly affected by wind or waves.

By way of example, it has been proposed to transport oil from Alaskas arctic north slope by nuclear-powered submarines which would travel beneath the surface of the ice to an ice-free port. It is desirable that such submarines not only receive oil at the ice-covered port, but that personnel can move between it and the surface.

As another example, it has been proposed to drill and/or service offshore wells or mines at considerable depths from an underwater caisson or service room, maintained at atmospheric pressure and equipped to house personnel. It is desirable to effect a communication between such a caisson and a submarine to transfer personnel.

It has been proposed (U.S. Pat. No. 2,783,970 to Gillespie) to attach separable pumping cabins to the bottom of a welldrilling submarine, which are detached and left in place as well heads when the wells have been completed. However, such cabins are not readily attached to the submarine while under water and cannot be used for docking the submarine; they, moreover, lack provision for removing water or altering the internal pressure in any space between the cabins and the submarine to permit watertight doors to be opened, or for joining the submarine to and separating it from the cabins.

Similarly, it has been proposed (US Pat. No. 3,063,507 to ONeill et al.) to provide a submersible well-drilling vessel with a detachable tank at the bottom and with man-carrying buoys at the top, the latter being moved on cables running to a surface vessel. Such installations require the use of pressure locks and/or have the drawbacks noted above and are not, therefore, suitable for mooring a submarine to another structure in a manner to permit the facile making of the connection while using hydrostatic pressure to maintain the connection while permitting the free passage of personnel through the connection.

It is the principal object to provide an underwater communicating connection between a water-immersed marine vessel and another structure that permits the free passage of personnel and/or goods without the use of air locks, and is provided with means for removing water from a space between the vessel and structure whereby they are urged together by the hydrostatic pressure of the water.

A related object is to provide a connection of the nature stated which can be readily unmade, to permit the marine vessel to move away from the structure.

A further, but optional, object is to provide means external to the connection for sealing the connection against entry of water into the communication passage formed by the connection. A related, alternate object is to provide simple means for sealing the vessel to the structure to prevent entry of water into said passage.

Still another object, realized in an optional embodiment. is to provide a mooring station or dock which includes a tower on the ground beneath the-water and an underwater communicating structure against which the marine vessel is placed in making the connection, to permit personnel passing through the connection to ascend to the surface.

Still another optional object is to provide an underwater caisson adapted to house personnel at subaqueous pressure and equipped with docking means for docking a submarine to transfer personnel between the caisson and submarine.

An additional optional object is to provide improved systems for positioning a vessel over a point, e.g., to position the submarine with its opening juxtaposed to or over the mating connection fitting of the structure and, preferably, to secure the vessel against movement relatively to the structure.

In summary, the underwater communicating connection between two enclosed structures containing air at subaqueous pressure, of which at least one is a marine vessel, comprises means on the two structures shaped to define between them a reception chamber, each structure having a normally closed, watertight door which when open interconnects the chamber and the interior of its respective structure, and means on one of said structures for removing water from said chamber to reduce the pressure therein and for providing therein air at subaqueous pressure; the latter usually includes means for admitting air into the chamber. When the pressure within the chamber equals or equals approximately that within the structures, the doors are opened, preferably into the reception chamber, to permit the free passage of personnel or goods.

The reception chamber initially contains water at the ambient pressure of the surrounding water. When water is removed from the chamber the two structures are forced together by the hydrostatic pressure of the surrounding water. When the vessel is a submarine this hydrostatic uniting force is effective regardless of the location of the connection on the submarine; but when it is a surface vessel, the connection must be at least partially horizontal.

The uniting force is transmitted between the structures by suitable abutments. In one form, the abutments are formed at the mouth of a reception chamber on one structure and on a frame on the other structure, and a compressible seal, such as a gasket, can be interposed between the abutments. In another form, the abutments have a mating surface which conforms to a part of a sphere to permit the vessel to tilt relatively to the other structure, and an annular seal, such as an O-ring is provided between the two structures.

In most embodiments there is also an external seal, such as a flexible sealing member fixed at its radially inner edge in sealed relation to one structure and pressed against a sealing surface on the other structure by the hydrostatic pressure of the surrounding water when the pressure within the chamber is being reduced, for preventing entry of water.

The connection further includes means for again increasing the pressure within the chamber after the doors have been closed, such as means for admitting a fluid such as sea water at the pressure of the surrounding water, to eliminate the uniting force and permit the two structures to move apart.

The means for removing water from the chamber may be a pump or a dump tank maintained at reduced pressure. Air can be supplied through a valve from one of the enclosed structures, or can be provided by expansion of a bubble of compressed air in one of the structures before juxtaposing them. The chamber can be again pressurized by opening another valve which admits water from the surrounding body of water.

As applied to a submarine, the connection may be at its bottom, and is then preferably directly below the center of gravity. However, it may be at some other location, such as a nose of a submarine. When the connection is a part of a mooring or docking installation, the outlet leads to a tower which extends to above the surface of the water. When the connection is at the nose of the submarine, it may be provided with a rotatable fitting to permit the submarine to swing about its mooring, e.g., through a circle of 360.

In another embodiment, the connection is provided between a submarine and an underwater caisson, such as a service room for the pumping of liquid or the drilling of a well.

For positioning the submarine, any of a variety of mechanisms may be used. According to one specific system, there are provided on the ground a pair of engageable fasteners, situated on opposite sides of the connection and engageable with anchors controlled by winches on the submarine, the anchor wires extending first vertically from the bow and stem but making angles to the vertical when engaged. By tightening the anchor wires by their winches, the submarine can be maneuvered to bring the submarine into proper juxtaposition to the other structure. The engageable fastener may include one or more pairs of side bars spaced above the ground and diverging from apices into which the anchors slide. According to a variant, each fastener includes a pair of laterally displaced apices, so that the submarine can be given a lateral as well as a longitudinal position by two or more anchors at the bow and a like number at the stem, the anchor wires being downwardly divergent when taught.

The vessel and the other structure may, additionally, be provided with positioning frames, such as male and female conical frames.

The invention will be further described with reference to the accompanying drawings, showing by way of example several preferred embodiments of the connection and alternative systems for positioning the vessel relatively to a docking station, wherein:

FIG. 1 is a perspective of a mooring station with a submarine in place;

FIG. 2 is a fragmentary perspective of the submarine hull, showing an anchor and its recess;

FIG. 3 is a plan of an engageable fastener;

FIG. 4 is an elevation of FIG. 3, part of the ground appearing in section;

FIG. 5 is an enlarged section taken on a plane transverse to the submarine and showing details of the connection;

FIG. 6 is a transverse sectional view through a submarine of a second embodiment, having a pair of stem anchors, only parts pertinent to the invention being shown;

FIG. 7 is a plan of the modified engageable fastener for use in the second embodiment;

FIG. 8 is a rear elevation of the submarine moored to the fastener of FIG. 7;

FIG. 9 is an enlarged section, taken on a plane longitudinal with respect to the submarine, of the connection of the second embodiment;

FIG. 10 is an elevation of a submarine having a nose-mooring and swung l80 from 'its initial position, showing a third embodiment of the invention;

FIG. II is a fragmentary plan of the ground platform about the mooring installation of FIG. 10;

FIG. 12 is an enlarged section taken on the longitudinal vertical central plane of the submarine of the third embodiment;

FIG. 13 is a fragmentary plan of a submarine moored similarly to FIG. 12 but showing a fourth embodiment, having a different anchor fastener;

FIG. 14 is a section taken on the line 14-14 of FIG. I3; and

FIG. I5 is a sectional view of a connection according to a fifth embodiment, suitable for use with an underwater caisson.

FIRST EMBODIMENT Referring to FIG. 1, a submarine 20 is immersed in a body of unfrozen water 21 beneath a surface layer of ice 22. The submarine is positioned over a reception chamber 23, which is fixed to'the ground 24 beneath the water, by bow and stem anchors 25, 26, which are engaged to engageable fasteners 27, 28, fixed to the ground. The anchors are connected by anchor wires 29 and 30 to winches (not shown) inside of the submarine. These winches may be driven hydraulically and adapted to operate when surrounded by water, although air may be present within the winch rooms at substantially the pressure of the surrounding water.

The reception chamber, shown in FIGS. 1 and 5, has an outlet leading to a tunnel 31 on the ground and which tunnel constitutes the enclosed structure containing air, e.g., at about atmospheric pressure, equal to that within the submarine. The tunnel leads to the interior of a tower 32 at its base. and the tower, which may be of concrete, extends to above the s$rface of the ice. It may contain an elevator 33 for transporting personnel or goods. The elevator may extend only as high as one story below the top deck, so that the central part of this deck can be clear to provide a platform 34 for the landing or aircraft, such as helicopters. The top deck may further carry derricks 35 and other facilities for servicing boats or ice sleds. The tower has a sufficient height to permit the submarine 20 to move above the chamber 23 and beneath the ice. The depth of the water at the top of this chamber may, for example, be 200 feet.

When the mooring station is for loading or unloading liquid, such as oil and fresh water, there may be one or more pipes 36 extending from the tower to shore and resting on the ground, and suitable control means (not shown) are provided in the tower. These pipes are connected to the submarines cargo space and/or water tanks by connections, which are not shown because they are not a part of this invention.

Referring to FIG. 5, the submarine 20 has, at its bottom 37, a communication member or frame 38 which provides a first, peripherally closed and downwardly directed abutment 39, surrounding a passage which extends upwardly and communicates with the interior of the submarine. This passage is normally closed by a watertight door 40 which engages a stop 41 in sealed relation and can be swung downwardly on a hinge 42. The abutment 39 bears, through a compressible sealing gasket 43, against a second, peripherally closed abutment 44 which surrounds the open mouth at the top of the reception chamber 23. The latter is flared downwardly at least laterally to accommodate the door 40 when it is swung into the chamber. A ladder 45 is mounted within the chamber, in alignment with a ladder 46 in the submarine. The bottom of the chamber has an outlet 47 which leads to the tunnel 31 and normally closed by a watertight door 48 which engages a stop 49 in sealed relation and has a hinge 50 on which it can be swung into the chamber. The chamber has secured to its exterior, by a clamping band 51, the radially inner edge of an annular, flexible sealing member 52, which may be formed of rubber or a synthetic material such as neoprene. This sealing member lies against a sealing surface formed by the part of the submarine hull 37 which surrounds the frame, 38, and is pressed upwards by the hydrostatic pressure of the surrounding water when the pressure within the chamber is reduced. The doors 40 and 48 are provided with latch mechanisms, operable from within the submarine and the tunnel 31, respectively.

Suitable means of any design are provided for removing water from the chamber 23 to reduce the pressure therein, for admitting air at subaqueous pressure thereinto, and, finally, for admitting a fluid under pressure thereinto. This may take the form of the following units: For rapidly removing the water, there is an external tank 53, located at a level below the chamber and connected to the chamber by a pipe 54 having a normally closed valve 55. This valve is controllable from within the tunnel 31 or tower 32, as by a pneumatic control line 56; however, other arrangements may be used, as by physically locating the operating handwheel of the valve within the tunnel or tower. The tank 53 is provided with a discharge pipe 57 connected to the intake of a small capacity water pump 58 which is controlled by a level-sensing device including a float 59. The tank 53 is normally maintained at subaqueous pressure and almost empty of water by the pump 58.

Air at the substantially atmospheric pressure of the tunnel I 31 can be admitted through a pipe 60 which extends between the upper part of the chamber 23 and the tunnel 31 and is normally closed by a valve 61 which is operable from within the tunnel. A branch pipe connects a pressure gage 62 to the part of the pipe 60 on the chamber side of the valve 61.

Sea water at the pressure of the surrounding water can be admitted into the chamber through a normally closed valve 63 having its intake in communication with the surrounding water. This valve is operable from within the tunnel 31, as by a pneumatic control line 64 (or other arrangements, as described for the valve 55).

Referring to FIGS. 3 and 4, there is shown the engageable fastener 28 for the stern anchor, the fastener 27 being of like construction but mounted in reversed direction. Each fastener comprises a pair of generally horizontal side members 65, 66, which are spaced above the ground and diverge from an apex 67. They are supported from and anchored to the ground by posts 68 and concrete piles 69. Advantageously, there is provided a smooth floor 70, e.g., a slab of concrete, at ground level in the area between the side members 65, 66, and extending out beyond the open end of the fastener. This slab promotes sliding of the anchor 25 or 26. In the embodiment shown, the posts 68 are anchored to the concrete slab 70 which is, in turn, fast to the piles 69.

Referring to F165. 2, 3 and 4, each anchor is formed of a substantially circular plate 71 having connected or fixed thereto a stem 72, which may have a length of several feet. The anchor wire 29 or 30 is secured to the upper end of the stem 72. The submarine hull has a circular recess 73 near the bow and the stern for receiving the circular anchor plates 71, so that the outer surfaces thereof lie flush with the hull exterior when the anchors are hauled in.

The fasteners 27 and 28 are located in a common line with the chamber 23, at distances that depend upon the interval between the bow and stem recesses 73. The interval between the structures 27 and 28 is different from the interval between the said recesses, so that the interval between their apices 67 is either smaller or greater, a greater distance being shown in this embodiment With such a greater spacing, the fasteners are oriented so that their apices 67 are directed toward each other; they would be pointed away from each other if the interval were smaller.

Suitable navigation guides of any desired type may be used. Those indicated here are merely exemplary, and include lights 74 and 75, mounted on the ground 24 on posts and in alignment with the fasteners 27 and 28; and a sonar transmitter 76 mounted above the tunnel 31 and directing sonar energy toward the side of the submarine, which has a pair of receiving transducers 77 and 78. The latter are connected to an indicator within the submarine to show when the longitudinal position of the submarine is such as to locate its abutment 39 directly above the abutment 44 on the reception chamber 23. Details of such an indicating system are known and, therefore, not described; see, for example, US. Pat. 3,100,006 to Sheets et a1.

OPERATION OF FIRST EMBODIMENT To make the connection, the submarine is moved along the line of the structures, directly over the fasteners 27 and 28,

and into the notch formed by the apex 67. During this movement the circular plate or disc 71 engages the undersides of the side members. As the submarine continues toward the lights 74 and 75 the anchor wire 30 to the stern anchor is paid out. The submarine is stopped when its bow anchor is above the floor 70 of the bow fastener 27; this anchor is then dropped and the submarine is reversed, causing the bow anchor 25 to engage the bow fastener. Final maneuvering of the submarine, in response to the indications of the sonar signals from the transducers 77 and 78, is by means of the anchor winches. The submarine can be lowered by means of these winches and its ballast tanks to place the abutments 39 and 44 together with the submarine horizontal. The flexible sealing member 52 thereby engages the sealing surface on the submarine hull.

The valve 55 is then opened, causing water from the chamber 23 to flow into the tank 53 and reducing the pressure within the chamber. When the water has been wholly or partially discharged, the valve 61 is opened, the gage 62 being first checked to insure that the valve is opened only after the pressure within the chamber has fallen to or below the pressure within the tunnel. The water level within the tank 53 rises, and the pump 58 is placed into operation by its level controller. If the pump has a low capacity, it will discharge water from the tank for a longer duration than that required to transfer the water from the chamber 23.

Reduction of the pressure within the chamber 23 to substantially less than the aqueous pressure surrounding the chamber causes the submarine to be urged against the reception chamber by hydrostatic pressure, the magnitude of which depends upon the depth of the water and the pressure of the air within the chamber. For example, when the depth of the top of the chamber is 200 feet below the ice surface, the water pressure is about 87 p.s.i. or greater, depending upon the salinity of the water and the thickness of the ice, which has a lower density than the water. lf the abutments 38 and 44 are circular and their inside diameters are 6 feet, the effective area is 4,071 sq. inches, and the submarine is pressed against the chamber with a force of about 177 tons, assuming that the pressure within the chamber is reduced to atmospheric pressure. This force maintains or aids in maintaining the connection by compressing the gasket 43 and aids in holding the submarine against shifting; the latter is further attained by the anchor wires, which are held taughtly. During the discharge of water from the chamber, if the gasket 43 is not uniformly compressed to effect a seal, tendency of water to flow into the chamber is prevented by the flexible sealing member 52, which is pressed by the water upwardly against the hull whenever the pressure in the space outside of the gasket 43 is less than that of the surrounding water. This sealing action can occur also later if, for any reason, the gasket 43 leaks.

After the air pressure within the chamber 23 equals that of the submarine and tunnel, the doors 40 and 48 are opened into the chamber 23, and personnel can descend from the interior of the submarine by the ladders 46 and 45, walk through the tunnel 31, and ascend the tower 32 by the elevator 33. Cargo can be similarly transported, as by pulling hoses through the chamber 23. However, in most instances other equipment will be provided for connecting the hoses to handle liquid cargo, which is flowed through the pipes 36.

To unmake the connection and detach the submarine from the docking installation, the doors 40 and 48 and the valves 55 and 61 are closed. Thereafter the valve 63 is opened, causing sea water to enter the chamber 23 until the pressure therein is equal to that of the surrounding water. A pocket of compressed air will be trapped at the top of the chamber 23. The pressures within and outside of the chamber being now equalized, the hydrostatic pressure pushing the submarine down no longer acts, and the submarine can ascend, as by the action of its ballast tanks, the anchor wires being loosened. It is first moved toward one end, e.g., toward the stern, using its propeller (aided, if desired, by the winch which winds the rear anchor wire) until the rear anchor attachment point passes beyond the fastener 28. The stern anchor 26 is thereby pulled our of the fastener and is thereafter hauled in. The submarine is then moved forwards to disengage the bow anchor from its fastener 27 in a similar manner; the bow anchor is thereafter hauled in.

SECOND EMBODIMENT FIGS. 6-9 show a second embodiment, employing positioning frames on the submarine and on the reception chamber, and using two bow and two stern anchors; these features may be applied individually.

Referring to FIGS. 6 and 9, the submarine, which may be a nuclear-powered vessel, has an inner, heavy shell or hull" 90 of standard construction, and a surrounding cargo space defined by the said shell and a thin, outer hull 91 which is connected to the inner shell by a framework 92. Winch chambers, located between radial walls 93, contain winches 94, constructed as previously described, on which are wound the anchor wires 95 and 96 of the stern anchors 97 and 98, respectively. A similar pair of winch chambers, winches and anchors is provided at the bow. These anchors are as was previously described. For engaging these anchors, there is provided on the ground a pair of engageable fasteners, positioned as were the fasteners 27 and 28 but in relation to the reception chamber 99. However, these fasteners are shaped, in plan, like the letter W," as appears in FIG. 7. The fasteners are of like construction and one of them is shown at 100. Each fastener has two pairs of side members, 101 and 102 in one pair and 103 and 104 in the other, each pair diverging from an apex 105 or 106 and spaced above a concrete slab 107 by posts 108, the slab being anchored in the ground by piles 109. As appears in FIG. 8, the lateral distance between the apices 105 and 106 is greater than that between the points of emergence of the anchor wires 95 and- 96 from the submarine, so that the anchor wires diverge outwardly to the sides to give the submarine a lateral position when the anchors are engaged to the fasteners and the wires are tightened. In addition, these wires are inclined in the fore-and-aft direction of the submarine, as described for the first embodiment. It is evident that the pair of fasteners, oppositely oriented, are mounted as previously described, and that the greatest spread between the side members 101 and 104 should exceed the interval between the anchors at one end of the submarine when they hang vertically, to insure that both anchors engage a pair of side members in the manner previously described.

Referring now to FIG. 9, the connection includes, on the submarine hull 90, a positioning frame 110 which is downwardly diverging, e.g., shaped as the frustum of a cone, and is provided at its upper end with a first, annular, downwardly directed abutment 111, which surrounds a passage communicating upwards into the interior of the submarine; it thereby constitutes the communicating member. This member carries a watertight door 112, which is normally closed against a sealing stop 113 and has a hinge 114 on which it can be swung downwardly into the upper part of the chamber 99. The bottom of the positioning frame 110 can be closed by a sliding door 115 which is substantially flush with the outer hull 91 and-is slidable into a pocket between that hull and awall 116.

The abutment 111 is pressed, through a compressible gasket 117, against a second, annular, upwardly directed abutment 118 formed at the top of a positioning frame 119 which forms the upper part of the chamber 99. This frame is upwardly convergent and has an external dimension to be spaced slightly from the interior of the frame 110 when the gasket 117 is compressed. The interior of the frame 119 is wide enough to receive the door 112. A ladder 120 is mounted within the chamber 99, in alignment with a ladder 121 in the submarine. The lower part of the chamber 99 has an outlet 122 which leads to the tunnel 31 and is normally closed by a watertight door 123 which is sealed against a peripheral stop 124 and can be swung into the chamber on a hinge 125. Suitable latch mechanisms permit the doors 112 and 123 to be opened from within the submarine and the tunnel 31, respectively. The exterior of the chamber 99 has sealed thereto, as by a clamping band 126, the radially inner edge of an annular, flexible sealing member 127, which bears against a sealing surface formed by the part of the submarine hull 91 which surrounds the bottom of the positioning frame 110.

It will be understood that the illustration is only diagrammatic, and that parts shown to be integral may be formed of any desired number of separate parts.

The means for removing water from the chamber 99, for admitting air thereinto, and for admitting fluid under aqueous pressure thereinto, may all be as previously described for the first embodiment, and only the parts 54-56 and 60-64 are shown, being identical with correspondingly numbered parts of FIG. 5.

OPERATION OF SECOND EMBODIMENT The connection is made and unmade as was described for the first embodiment, with the following differences:

a. the multiple anchors at each end of the submarine are engaged to the fasteners a pair at a time, and they position the submarine laterally as well as along its axis. The lateral action is illustrated in FIG. 8, showing the anchor wires and 96 to be downwardly divergent. They are, additionally, downwardly divergent along the submarine axis, as shown in FIG. 1.

b. The positioning frames 1 10 and 119 aid in positioning the submarine relatively to the chamber 99, so that the exact location of the submarine above the stationary reception chamber prior to the final descent is not critical.

c. The sliding door is opened prior to lowering the submarine (by remote-control door-actuating means, not shown) to permit the frame 119 to enter the frame 110. This door is slid to close the bottom of the frame 110 after the submarine has ascended to present a smooth outer surface. It may be noted that an air pocket is formed within the frame 110 when the submarine is detached from the chamber. This air may be dispelled by pipes and valves, not shown, or may be maintained and the frame 110 can be used as an auxiliary ballast tank, if desired. Flow connections for this purpose are not shown since they are not a part of this invention and are obvious to persons skilled in the art.

THIRD EMBODIMENT FIGS. 10-12 show the third embodiment, wherein the connection is at the nose of the submarine; optionally, as shown, the submarine can swing through any desired horizontal angle, such as 360, about its mooring.

In this embodiment, the submarine has at its bow a tubular, forward projection 136 which has a ball or segment of a sphere 137 at its front end. The ball has an external diameter slightly greater than that of the projection 136, which may be circular in cross section. The projection and ball have a central passageway, of size to permit personnel to walk, and this passage is normally closed at its forward end by a watertight door 138 having a hinge on which it can be swung forwardly. The stem of the submarine has a heavy anchor 139, connected by an anchor wire 140 to a winch (not shown) within the submarine. When the submarine is moored this anchor rests on the ground or, preferably, on a smooth, annular platfon'n, such as an annular slab of concrete 141.

The docking installation includes the tunnel 31, as previously described but located below the ground to accommodate the platform 141, and a communicating tower 32, constructed as was described for the first embodiment. The tunnel 31 communicates via a passage 142, which is normally closed by a watertight door 143, to the bottom of a chamber 144 which is stationary on the ground 24. The door 143 has a hinge 145 on which it can be swung into the chamber. Mounted for rotation on a vertical axis is a swivel head 146 having at the top a communicating horizontal section 147. This horizontal section has a width sufficient to receive the submarine door 138 and a height great enough to permit personnel to walk through it. Its floor is flat to permit personnel to reach a ladder 148, which is stationary and is mounted within the chamber by brackets 149. The head is rotatably supported by suitable thrust and radial bearings, diagrammatically indicated at 150, and is sealed against entry of sea water by rings 15], which are positioned by supporting rings 152, the latter being bolted in watertight relation to the ceiling 153 of the chamber.

The swivel head can be rotated by means of an electric motor 154, which is controlled from the tunnel. The motor has a gear pinion 155 meshing with an internal gear ring 156 which is fixed inside the head. A series of control lines, indicated at 157, permit the motor to be controlled from the tunnel, and also provide an indication of the orientation of the swivel head, e.g., by selsyn motors, not shown. The control lines 157 further control a clutch to disconnect the motor 154 from the driving gears, to permit the swivel head to rotate freely.

The horizontal section 147 carries or has formed thereon a horizontal tubular section 158 having at its end a flaring section 159. The internal cross section of the tubular section 158 is circular, having a diameter just slightly larger than that of the ball 137, and its inner end is hemispherical in shape, but relieved at the extreme end to provide access to the door 138. Thereby the hemispherical end of the section 158 forms an abutment for the end of the ball 137 and the latter, together with the submarine, can be tilted through a limited angle, such as The hemispherical surface carries suitable sealing means, such as O-rings 160, which bear against the ball 137 to prevent the inflow of water into the head. Optionally, a flow passage, such as one or more longitudinal grooves 161, is formed in the inner surface of the section 158, to permit water to escape from the space in front of the ball 137 as it moves into the section 158, this flow being against resistance caused by providing grooves of only small cross section.

The chamber 144 is provided with suitable means for removing water therefrom to reduce its internal pressure, for admitting air at sub-aqueous pressure into it, and for admitting fluid at aqueous pressure into it. These may take the form of the parts 54, 55 and 60-64, as described for the first embodiment, together with the tank 53 and its pump, all as shown in FIG. 5. In addition, the chamber preferably has a check valve which discharges to the surrounding water through a restrictive pipe 163 whenever the pressure within the chamber exceeds that of the surrounding water, while imposing some resistance to the outflow of water.

Suitable navigation aids, not a part of this invention, are provided to guide the submarine into the swivel head section 158. Such a system may include a pair of laser beam sources 164 and 16S, mounted on the tower 32 and adapted to be received by fore and aft laser beam receivers 166 and 167 on the submarine. For initially directing the submarine to pick up these lasar beams, a navigation light 168 on the tower is provided, to be viewed from the control room in the conningtower 169 or through a periscope.

OPERATION OF THIRD EMBODIMENT The swivel head is initially oriented with its flaring section 159 directed away from the tower 32, by means of the motor 154. Before the submarine is docked, the swivel head 146 and the chamber 144 are full of water at the local pressure. The laser beams and navigation light, 164, 165 and 168 being turned on, the submarine advances toward the tower and moves its ball 137 into the flaring section 159 and, thence, into the tubular section 158. Although the submarine is moving very slowly, it has momentum, and this is overcome by the restrictive escape of water which is trapped in front of the ball 137. When the groove 161 is provided, water escapes through it; when not, it escapes through the check valve 162 and pipe 163. When the ball reaches the hemispherical abutment, the O-rings 160 effect a seal. It may be noted that, in lieu of the check valve 162 and pipe 163, it is possible to provide a compressible element, such as a pocket of gas sealed in bags or in an inverted dome, to receive water which enters the chamber during the last inch or so of travel of the ball 137 and which cannot flow out through the groove 161.

As the submarine head enters the flaring section, its stern anchor 139 is dropped onto the platform 14 and the stern buoyancy is adjusted to keep the anchor wire 140 taught. This will maintain the stem at the correct height to make the submarine horizontal.

When the submarine is in position as shown in FIGS. 10 and 12, the valve 55 is opened to reduce the pressure within the chamber 144 and the swivel head 146, and to remove water therefrom through the pipe 54. Prior to this time the O-rings 151 were inactive, the water pressure being the same on both sides. This reduction of pressure makes them active to prevent the entry of water downward about the swivel head. The reduction in pressure also causes the submarine to be pressed against the swivel head by hydrostatic pressure. After air is admitted by means of the valve 61, the doors 138 and 143 are opened to permit the passage of personnel.

The submarine is free to rotate about the vertical axis of rotation of the swivel head throughout 360; in FIG. 10 it is shown after rotating through [80 from the docking position. To permit free rotation of the submarine and its swivel head, the motor 154 is declutched. As the submarine turns, its anchor is dragged on the surface of the annular platform 141. Should a reversal of direction occur, the anchor line assumes a vertical position, thereby slightly raising its stern; however, such minor tilting of the submarine is possible due to the spherical shapes of the abutments at the front of the ball 137.

Although the third embodiment includes a swivel head 146 and an annular anchor platform 141 to permit swinging of the submarine, as in response to water currents, this swinging is not in every case necessary. The construction can be simplified by forming the head 146 in fixed relation to the chamber 144 (with its flaring section 159 directed away from the tower 32). The stern of the submarine can then be anchored by other means, such as a single or a pair of stem anchors secured by the engageable fasteners previously described for FIGS. 1, 3 and 4 or 7 and 8.

The connection is unmade as previously described, by closing the doors 138 and 143 and the valves 55 and 61, opening the valve 63, and moving the submarine in reverse.

FOURTH EMBODIMENT FIGS. 13 and 14 show a variant of the anchoring arrangement, suitable for use with the nose-mooring construction of the third embodiment. The annular slab 141 is replaced by an annular track having a circular slot 171 leading downwardly into a radially enlarged recess 172 of size to receive the plate 71 of the anchor described for the first embodiment, the anchor stem 72 extending upwards through the slot. The radius of the slot 171 about the vertical axis of rotation of the swivel head 146 is greater than the distance from this axis to the point of emergence of the anchor from the submarine, whereby the anchor wire is inclined downwardly away from the axis. To permit entry of the anchor into the recess, there is a mouth 173, directed away from the tower 32 and situated outwardly of the slab or track 171. This mouth has flaring sides, which arise from a concrete slab therebetween; the inner ends of these sides may be similarly flared, as indicated at 174, 0 permit the anchor to be withdrawn more readily, and these sides may also be undercut. The sides of the slot, the recess, and the sides of the mouth may, if desired, be lined with metal.

OPERATION OF FOURTH EMBODIMENT The submarine, moving toward its mooring as described for the third embodiment, drops its stern anchor onto the concrete slab in the mouth 173, and drags the anchor into the recess 172. This recess is sufficiently high to receive the plate 71 although it is not horizontal, and the stem 72 extends through the slot 171 at a slight angle to the vertical. When the submarine swings about the chamber 144, the anchor is dragged through the recess 172 along the circular track.

To disengage the submarine anchor, the submarine is directed away from the tower 32 and moved forwardly, causing the anchor to enter the mouth, which it finds readily due to the flared parts 174.

FIFTH EMBODIMENT FIG. shows an embodiment in which the submarine is used to move personnel and/or goods to and from an underwater caisson, which may rest on the ground at any desired depth of water, such as several thousand feet. The means for varying the pressure within the reception chamber are, in this embodiment, located on the submarine, thereby obviating the need to have personnel in the caisson to operate this equipment.

The caisson 175 is sealed against entry of water and rests on the ocean bottom 176; it may have a concrete base slab 177, to which the outside walls are sealed and an additional, external seal in the form ofa flexible flap 178 may be provided. The flap is pressed against the concrete slab by the water if there is a leak in the connection to the walls. The caisson is maintained at or at about atmospheric pressure and contains air, for containing personnel. If desired, additional anchoring means, not shown, can be employed, but usually it is heavy enough to prevent any tendency toward flotation. The caisson may be used, for example, as a service room to drill, complete or produce oil from a well 179, and for this purpose includes a tower-shaped room 180 which contains the necessary equipment, only a pulley 181 being shown. This room may be isolated from the room 182 by a bulkhead 183 having a watertight door 184. Lengthy equipment, such as drill pipe, can be transported through a watertight door 185, using special equipment or locks, not shown.

The roof 186 of the caisson room 182 contains a positioning frame 187 which is upwardly divergent, e.g., shaped as the frustum of a cone. It has at its bottom a passage which is normally closed by a watertight door 188, operable at least from the top but, preferably, from both top and bottom. This door has a hinge on which is can be swung upwards. The top of the frame is formed with an annular abutment 189 on which is a compressible sealing gasket 190. A flexible sealing member 191 is sealingly clamped at its radially inner edge to the top of the frame by a clamping band 192. The caison contains, fixed therein, a ladder 193 extending to the door 188.

A part 194 of a submarine 195 has a horizontal partition or deck 196 with an opening passage which is normally sealed by a watertight door 197. The latch on this door is operable from above and the door has a hinge on which it can swing downwardly into a reception chamber 198 which is fixed to the deck and to the hull part 194. The bottom of this chamber is formed as a male positioning frame 199, which is downwardly convergent, having a shape like the inner surface of the frame 187 but of slightly smaller diameter so as to permit a downwardly directed annular abutment outside of the frame 199 to compress the gasket 190. When the parts are united as shown the flexible member 191 engages a sealing surface on the submarine, constituted by the part of the hull 194 surrounding the frame 199. The reception chamber 198 and frame 199 carry a ladder 200, aligned with the ladder 193 and extending to the door 197.

For varying the pressure within the chamber 198 and frame 199 there is a pipe 201, open at its bottom intake end, and connected to the suction side of a.pump 202. This pump is discharged through a valve 203 to a pipe 204. The pump and valve are shunted by a valve 205 and pipe 206 to admit water from the pipe 204 to the pipe 201. Air from the submarine can be admitted into the reception chamber by a pipe 207 which extends through the deck 196 and a valve 208, a pressure gage 209 being connected to this pipe on the reception chamberside ofthe valve 208.

OPERATION or FIFTH EMBODIMENT The submarine is positioned with its positioning frame above the positioning frame 187 by any suitable means, such as those previously described and it is lowered to seat on the gasket 190. The two frames aid in positioning the submarine precisely on the caisson This causes the sealing member 191 to engage the bottom of the hull portion 194. The part of the frame 187 above the closed door 188 and the reception chamber, or at least the lower part thereof, are initially filled with water at the pressure of the surrounding water. During this operation the door 197 and all valves except, optionally, the valve 205 are closed.

The valve 205 is closed, valve 203 is opened, and water is removed through the pipes 201 and 204 by operating the pump 202. Thereby I the pressure within the reception chamber is reduced and the submarine is pressed against the caisson by hydrostatic pressure. During this operation the sealing member 191 is pressed firmly against the hull portion 194 by the pressure of the water until the gasket makes a seal. Some water may remain at the bottom of the space above the door 188, depending upon the length of the pipe 201.

Air at the pressure prevailing within the submarine is then (or simultaneously) admitted via the valve 208, the gage 209 being checked to make certain that the pressure is less than that of the submarine before opening the valve. The valve 203 is then closed and the pump 202 is stopped. The door 197 is then opened, and personnel descend the ladder 200 and open the door 188. If water is present on top of this door it enters the room 182, from which is can be removed by suitable pumps, not shown.

To separate the submarine, the doors 188 and 197 are closed, the valve 208 is closed, and the valve 205 is opened to admit water at the pressure of the surrounding water through the pipe 201. This releases the hydrostatic pressure and the submarine is free to ascend.

1n the embodiment shown, a small bubble of air will remain at the top of the chamber 198 after the chamber is pressurized. its size will depend upon the water pressure and the pressure of the air in the submarine. 1f the water depth is, say, 1,500 feet and the submarine is at atmospheric pressure, the air will be compressed to about one forty-fifth of its former volume. If this bubble of air is always present, it will expand to substantially fill the chamber, including the positioning frame 199, during the next docking operation as water is evacuated by the pump 202. This may obviate the need for the valve 208 to admit air.

I claim:

1. In an underwater communicating connection between two enclosed structures containing air at subaqueous pressure, said structures being relatively movable apart from the connection and at least one being a water-immersed marine vessel, the combination of a. means on each of said structures shaped to define cooperatively a reception chamber between the structures which is isolated from the ambient water, each structure having a watertight door which leads to the interior of the respective structure, said doors being spaced apart and, when closed, isolating said chamber, the parts of said chamber on both structures being in communication with the ambient water when said structures are separated, and

b. means on one of said structures for removing water from said chamber to reduce thereby the pressure therein and for providing therein air at said subaqueous pressure, whereby said structures are urged together by hydrostatic pressure and said doors can be both opened at the same time.

2. A connection according to claim 1 wherein said vessel is a submerged submarine and said other structure is fixed to the ground beneath the water and includes means extending from said ground to the water surface and providing a continuous passage from the interior of said chamber to the surface.

3. A connection according to claim 1 wherein both of said doors are mounted for movement into the reception chamber.

4. A connection according to claim 1 wherein said means defining the reception chamber includes a. an open reception chamber on one structure providing a peripherally closed, vertically directed abutment in the direction of the open end of the chamber, one door being in the wall of said chamber remote from the opening thereof, and

b. a frame on the other structure providing a peripherally closed, vertically directed abutment conforming to and opposed to the first-mentioned abutment, said frame providing a passage to said other structure within the latter abutment and containing the other door.

5. A connection according to claim 4 wherein said frame and other door are located at the bottom of a submarine and the said other door is approximately flush with the said bottom.

6. A connection according to claim 1 wherein the connection is formed at an end of a submarine which constitutes the said marine vessel, the means on the submarine for defining cooperatively the reception chamber being rigid with the hull of the submarine and presenting a horizontal directed first abutment, and the means on the other structure providing a horizontally directed second abutment adapted for sealing engagement with the first abutment.

7. A connection according to claim 1 wherein said marine vessel is a submarine immersed in water and the connection is formed in an end of the submarine, which includes a. a stationary chamber on the ground beneath the water,

and

b. a swivel head rotatable about a vertical axis and communicating with said stationary chamber, said swivel head having a horizontal section providing an abutment directed outwardly from said axis,

c. an end part of said submarine being in abutment with said abutment on the swivel head, whereby the submarine can swing about said axis together with the swivel head.

8. In combination with the connection according to claim 7, annular means on the ground surrounding said stationary chamber and concentric with said vertical axis, for supporting an anchor from the submarine as the submarine rotates about said axis.

9. A connection according to claim 1 wherein said marine vessel is a submarine submerged in water and the connection is formed in an end of the submarine, and wherein the means for cooperatively defining the reception chamber includes a. on one structure a projection ending in an enlarged ball the end surface of which has the shape of a sphere, said ball having extending therethrough a passage communicating through said projection with the interior of the respective structure, and

b. on the other structure a tubular body of internal diameter to receive said ball and shaped to provide, at its inner end, an abutment the surface of which is in conformity to the ball for tilting movement between the ball and the latter structure, said abutment having a passage extending therethrough for registry with the passage through the ball,

c. the element of said ball-and-tubular body combination which is on the submarine being at one end of the submarine and rigid relatively to the hull thereof.

107 A connection according to claim 1 wherein said marine vessel is a submarine submerged in water and the connection is formed in an end of the submarine, and wherein the means for cooperatively defining the reception chamber includes a. on one structure a segment of a sphere formed with a passage extending therethrough which communicates with the interior of the respective structure, and b. on the other structure l. a tubular body of internal diameter to receive said segment with only a slight clearance having at its inner end an abutment shaped to seat against said segment and having a passage extending through the abutment for registry with said passage through the segment, said tubular body having a length sufficient to permit sliding movement of the segment therethrough before reaching the abutment, and 2. means for discharging from said tubular body against pressure, water that is trapped in front of the segment as it moves toward the abutment, for absorbing the momentum of the submarine.

11. A connection according to claim 1 wherein said marine vessel is a submarine submerged in water and the connection is formed in an end of the submarine, which includes a. on one end of the submarine, a projection ending in a segment of a sphere the surface of which remote from the submarine is convex, said segment having extending therethrough a passage communicating with the interior of the submarine,

b. on the other structure, a tubular body of internal diameter to receive said segment and shaped to provide, at its inner end, an abutment shaped to seat said segment and having a passage extending through the abutment for registry with the said passage through the segment, and

c. at least one set of O-rings between said tubular body and said segment for sealing the said other structure against entry of water about said segment.

12. In combination with the connection according to claim 1, wherein said vessel is a submarine and said other structure is fixed to the ground beneath the water and the submarine and the other structure have opposed abutments which, when brought together in alignment, close said reception chamber, means independent of the connection for positioning the submarine relatively to said other structure so as to bring said abutments into approximate alignment and juxtaposition.

13. A connection according to claim 12 wherein the means for positioning the submarine includes a. a pair of engageable fasteners fixed relatively to the ground beneath the water on opposite sides of the abutment on said other structure, and

b. a pair of anchor means connected to the submarine by anchor wires at axially spaced locations thereon, each anchor wire being wound about a winch drum which is controllable from within the submarine, said anchor means being engageable with said fasteners.

14. A connection according to claim 13 wherein a. each fastener includes a pair of generally horizontal side members that are positioned above said ground and diverge from an apex, the apices of said fasteners being oriented in mutually opposite directions, and

b. said anchor means include laterally extended, upwardly directed surfaces adapted to slide along the under sides of said fastener side members.

15. In combination with the connection according to claim 1, means for admitting fluid under at least ambient water pressure into said reception chamber for releasing the structures after the doors are closed.

16. In a structure for positioning a vessel immersed in water with a point on the vessel approximately over a point fixed on the ground beneath the water, the combination of a. a pair of engageable fasteners fixed relatively to said ground on opposite sides ofsaid point, and

b. a pair of anchor means on the vessel at longitudinally spaced locations on the vessel, the interval between said fasteners being different from that between said locations, each anchor means being provided with a winding winch on and controllable from the vessel and an anchor wire passing about said winch and connected to the anchor means, said anchor means being engageable to the fastener,

0. whereby said wires are inclined to the horizontal when extending from the vessel to the respective fasteners when the vessel is positioned over said point.

17. The structure defined in claim 16 wherein a. each fastener includes a pair of generally horizontal side members that are positioned above said ground and diverge from an apex, the apices of said fasteners being oriented in opposite directions, and

b. said anchor means include laterally extended, upwardly directed surfaces adapted to slide along the under sides of said side members, and a stem adapted to slide along said side members into an apex.

18. The structure defined in claim 16 wherein a. the vessel has at least a pair of anchor means at each longitudinal end thereof,

b. each fastener has at least two pairs of side members that are spaced above the said ground and are generally horizontal and provide at least a pair of apices, in the nature of the letter W, and

c. the lateral interval between the apices of the same fastener is different from the lateral interval between the points of emergence of the anchor wires at the same end of the vessel, whereby the vessel can be positioned laterally.

19. In an underwater dock for submarines for the transfer of personnel to an from said submarine, a dock structure fixed to the ground beneath the water,said dock structure including an enclosed space at substantially atmospheric pressure for personnel and a reception chamber with a mouth which is beneath and normally in communication with the water and is shaped to engage a part .of the submarine to effect a watertight seal therewith, said part of the submarine including a passage leading to the interior thereof, an outlet for the chamber leading to said space, a watertight door normally closing the outlet an spaced from the mouth, and means for reducing the pressure within the reception chamber between the mouth and the door to below the pressure of the ambient water for securing said submarine to the chamber by hydrostatic pressure and supplying air to the chamber at substantially atmospheric pressure to permit said door to be opened.

20. In combination with the dock according to claim 19, means for introducing a fluid under at least ambient water pressure into said chamber for dispelling said hydrostatic pressure.

21. In an underwater communicating connection between two enclosed structures containing air at subaqueous pressure, said structures being relatively movable apart from the connection and at least one being a water-immersed marine vessel, the combination of:

a. means on each of said structures shaped to define cooperatively a reception chamber between the structures which is isolated from the ambient water, each structure having a watertight door which leads to the interior of the respective structure, said doors being spaced apart and, when closed, isolating said chamber, and

b. a flexible annular sealing member fixed at its radially inner edge in sealed relation to one of said structures and extending unsupportedly outwardly to its radially outer edge, said flexible sealing member lying in sealing relation on a sealing surface of the other of said structures.

22. In an underwater communicating connection between two enclosed structures containing air at subaqueous pressure, said structures being relatively movable apart from the connection and at least one being a water-immersed marine vessel, the combination of:

a. means on each of said structures shaped to define cooperatively a reception chamber between the structures which is isolated from the ambient water, each structure having a watertight door which leads to the interior of the respective structure and each of said means having an abutment element shaped to mate with the other, and

b. a male centering frame on one structure and a female centering frame on the other structure, said frames being convergent in a common direction, for moving the vessel into position to place said abutments into alignment as the vessel moves toward the other structure.

23. The method of mooring a submerged submarine the interior of which contains air substantially at atmospheric pressure and having a structure shaped to abut in watertight relation and the mouth of an underwater reception chamber which 15 normally in communication with the ambient water and has a space for personnel containing air at substantially atmospheric pressure, said space being in communication with the reception chamber through a watertight door, there being also a watertight door on the submarine at the said structure thereof, which comprises the steps of:

a. positioning said submarine to bring the said structure thereon into juxtaposition to the mouth of said chamber while both of said doors are closed and isolating the chamber from the ambient water,

b. removing water from said chamber and reducing the pressure therein, thereby causing the submarine structure to be urged against the mouth of the chamber by hydrostatic pressure, and

. opening both of said doors while the pressure within the chamber is substantially atmospheric to permit the passage of personnel between the interior of the sub marine and said space of the dock through the resulting continuously open passage.

24. The method according to claim 23 wherein said water is removed from the chamber by flow into a container maintained at a pressure lower than that of the ambient water. 

1. In an underwater communicating connection between two enclosed structures containing air at subaqueous pressure, said structures being relatively movable apart from the connection and at least one being a water-immersed marine vessel, the combination of a. means on each of said structures shaped to define cooperatively a reception chamber between the structures which is isolated from the ambient water, each structure having a watertight door which leads to the interior of the respective structure, said doors being spaced apart and, when closed, isolating said chamber, the parts of said chamber on both structures being in communication with the ambient water when said structures are separated, and b. means on one of said structures for removing water from said chamber to reduce thereby the pressure therein and for providing therein air at said subaqueous pressure, whereby said structures are urged together by hydrostatic pressure and said doors can be both opened at the same time.
 2. A connection according to claim 1 wherein said vessel is a submerged submarine and said other structure is fixed to the ground beneath the water and includes means extending from said ground to the water surface and providing a continuous passage from the interior of said chamber to the surface.
 2. means for discharging from said tubular body against pressure, water that is trapped in front of the segment as it moves toward the abutment, for absorbing the momentum of the submarine.
 3. A connection according to claim 1 wherein both of said doors are mounted for movement into the reception chamber.
 4. A connection according to claim 1 wherein said means defining the reception chamber includes a. an open reception chamber on one structure providing a peripherally closed, vertically directed abutment in the direction of the open end of the chamber, one door being in the wall of said chamber remote from the opening thereof, and b. a frame on the other structure providing a peripherally closed, vertically directed abutment conforming to and opposed to the first-mentioned abutment, said frame providing a passage to said other structure within the latter abutment and containing the other door.
 5. A connection according to claim 4 wherein said frame and other door are located at the bottom of a submarine and the said other door is approximately flush with the said bottom.
 6. A connection according to claim 1 wherein the connection is formed at an end of a submarine which constitutes the said marine vessel, the means on the submarine for defining cooperatively the reception chamber being rigid with the hull of the submarine and presenting a horizontal directed first abutment, and the means on the other structure providing a horizontally directed second abutment adapted for sealing engagement with the first abutment.
 7. A connection according to claim 1 wherein said marine vEssel is a submarine immersed in water and the connection is formed in an end of the submarine, which includes a. a stationary chamber on the ground beneath the water, and b. a swivel head rotatable about a vertical axis and communicating with said stationary chamber, said swivel head having a horizontal section providing an abutment directed outwardly from said axis, c. an end part of said submarine being in abutment with said abutment on the swivel head, whereby the submarine can swing about said axis together with the swivel head.
 8. In combination with the connection according to claim 7, annular means on the ground surrounding said stationary chamber and concentric with said vertical axis, for supporting an anchor from the submarine as the submarine rotates about said axis.
 9. A connection according to claim 1 wherein said marine vessel is a submarine submerged in water and the connection is formed in an end of the submarine, and wherein the means for cooperatively defining the reception chamber includes a. on one structure a projection ending in an enlarged ball the end surface of which has the shape of a sphere, said ball having extending therethrough a passage communicating through said projection with the interior of the respective structure, and b. on the other structure a tubular body of internal diameter to receive said ball and shaped to provide, at its inner end, an abutment the surface of which is in conformity to the ball for tilting movement between the ball and the latter structure, said abutment having a passage extending therethrough for registry with the passage through the ball, c. the element of said ball-and-tubular body combination which is on the submarine being at one end of the submarine and rigid relatively to the hull thereof.
 10. A connection according to claim 1 wherein said marine vessel is a submarine submerged in water and the connection is formed in an end of the submarine, and wherein the means for cooperatively defining the reception chamber includes a. on one structure a segment of a sphere formed with a passage extending therethrough which communicates with the interior of the respective structure, and b. on the other structure
 11. A connection according to claim 1 wherein said marine vessel is a submarine submerged in water and the connection is formed in an end of the submarine, which includes a. on one end of the submarine, a projection ending in a segment of a sphere the surface of which remote from the submarine is convex, said segment having extending therethrough a passage communicating with the interior of the submarine, b. on the other structure, a tubular body of internal diameter to receive said segment and shaped to provide, at its inner end, an abutment shaped to seat said segment and having a passage extending through the abutment for registry with the said passage through the segment, and c. at least one set of O-rings between said tubular body and said segment for sealing the said other structure against entry of water about said segment.
 12. In combination with the connection according to claim 1, wherein said vessel is a submarine and said other structure is fixed to the ground beneath the water and the submarine and the other structure have opposed abutments which, when brought together in alignment, close said reception chamber, means iNdependent of the connection for positioning the submarine relatively to said other structure so as to bring said abutments into approximate alignment and juxtaposition.
 13. A connection according to claim 12 wherein the means for positioning the submarine includes a. a pair of engageable fasteners fixed relatively to the ground beneath the water on opposite sides of the abutment on said other structure, and b. a pair of anchor means connected to the submarine by anchor wires at axially spaced locations thereon, each anchor wire being wound about a winch drum which is controllable from within the submarine, said anchor means being engageable with said fasteners.
 14. A connection according to claim 13 wherein a. each fastener includes a pair of generally horizontal side members that are positioned above said ground and diverge from an apex, the apices of said fasteners being oriented in mutually opposite directions, and b. said anchor means include laterally extended, upwardly directed surfaces adapted to slide along the under sides of said fastener side members.
 15. In combination with the connection according to claim 1, means for admitting fluid under at least ambient water pressure into said reception chamber for releasing the structures after the doors are closed.
 16. In a structure for positioning a vessel immersed in water with a point on the vessel approximately over a point fixed on the ground beneath the water, the combination of a. a pair of engageable fasteners fixed relatively to said ground on opposite sides of said point, and b. a pair of anchor means on the vessel at longitudinally spaced locations on the vessel, the interval between said fasteners being different from that between said locations, each anchor means being provided with a winding winch on and controllable from the vessel and an anchor wire passing about said winch and connected to the anchor means, said anchor means being engageable to the fastener, c. whereby said wires are inclined to the horizontal when extending from the vessel to the respective fasteners when the vessel is positioned over said point.
 17. The structure defined in claim 16 wherein a. each fastener includes a pair of generally horizontal side members that are positioned above said ground and diverge from an apex, the apices of said fasteners being oriented in opposite directions, and b. said anchor means include laterally extended, upwardly directed surfaces adapted to slide along the under sides of said side members, and a stem adapted to slide along said side members into an apex.
 18. The structure defined in claim 16 wherein a. the vessel has at least a pair of anchor means at each longitudinal end thereof, b. each fastener has at least two pairs of side members that are spaced above the said ground and are generally horizontal and provide at least a pair of apices, in the nature of the letter ''''W,'''' and c. the lateral interval between the apices of the same fastener is different from the lateral interval between the points of emergence of the anchor wires at the same end of the vessel, whereby the vessel can be positioned laterally.
 19. In an underwater dock for submarines for the transfer of personnel to an from said submarine, a dock structure fixed to the ground beneath the water, said dock structure including an enclosed space at substantially atmospheric pressure for personnel and a reception chamber with a mouth which is beneath and normally in communication with the water and is shaped to engage a part of the submarine to effect a watertight seal therewith, said part of the submarine including a passage leading to the interior thereof, an outlet for the chamber leading to said space, a watertight door normally closing the outlet an spaced from the mouth, and means for reducing the pressure within the reception chamber between the mouth and the door to below the pressure of the ambient water for securing said submarine to the chaMber by hydrostatic pressure and supplying air to the chamber at substantially atmospheric pressure to permit said door to be opened.
 20. In combination with the dock according to claim 19, means for introducing a fluid under at least ambient water pressure into said chamber for dispelling said hydrostatic pressure.
 21. In an underwater communicating connection between two enclosed structures containing air at subaqueous pressure, said structures being relatively movable apart from the connection and at least one being a water-immersed marine vessel, the combination of: a. means on each of said structures shaped to define cooperatively a reception chamber between the structures which is isolated from the ambient water, each structure having a watertight door which leads to the interior of the respective structure, said doors being spaced apart and, when closed, isolating said chamber, and b. a flexible annular sealing member fixed at its radially inner edge in sealed relation to one of said structures and extending unsupportedly outwardly to its radially outer edge, said flexible sealing member lying in sealing relation on a sealing surface of the other of said structures.
 22. In an underwater communicating connection between two enclosed structures containing air at subaqueous pressure, said structures being relatively movable apart from the connection and at least one being a water-immersed marine vessel, the combination of: a. means on each of said structures shaped to define cooperatively a reception chamber between the structures which is isolated from the ambient water, each structure having a watertight door which leads to the interior of the respective structure and each of said means having an abutment element shaped to mate with the other, and b. a male centering frame on one structure and a female centering frame on the other structure, said frames being convergent in a common direction, for moving the vessel into position to place said abutments into alignment as the vessel moves toward the other structure.
 23. The method of mooring a submerged submarine the interior of which contains air substantially at atmospheric pressure and having a structure shaped to abut in watertight relation and the mouth of an underwater reception chamber which is normally in communication with the ambient water and has a space for personnel containing air at substantially atmospheric pressure, said space being in communication with the reception chamber through a watertight door, there being also a watertight door on the submarine at the said structure thereof, which comprises the steps of: a. positioning said submarine to bring the said structure thereon into juxtaposition to the mouth of said chamber while both of said doors are closed and isolating the chamber from the ambient water, b. removing water from said chamber and reducing the pressure therein, thereby causing the submarine structure to be urged against the mouth of the chamber by hydrostatic pressure, and c. opening both of said doors while the pressure within the chamber is substantially atmospheric to permit the passage of personnel between the interior of the submarine and said space of the dock through the resulting continuously open passage.
 24. The method according to claim 23 wherein said water is removed from the chamber by flow into a container maintained at a pressure lower than that of the ambient water. 